The invention is in the field of optical waveguide interconnection technology, and is to be applied in the structural configuration of a fiber-optic endpiece. The fiber-optic endpiece includes a base member, which has a rear side and a coupling end face, a fixing member, having a front and a rear face, and at least one optical waveguide fixed in a groove between the base member and the fixing member.
In a conventional fiber-optic endpiece of this type, as is shown in International Publication No. WO 97/34179, the fixing member is pushed into a depression in the base member along the guide structures thereof, and clamped, in the pushed-in state, in the depression by interaction of its guide surfaces with the guide structures of the base member. The depression and the groove and the optical waveguide fixed therein extend up to the coupling end face. In this case, the cross section of the depression and of the fixing member diminishes along the depression in the direction of the coupling end face. The front face of the fixing member is wider than the cross-sectional width of the depression in the plane of the coupling end face, with the result that the fixing member cannot be pushed with its front face up to the coupling end face of the base member. Consequently, the optical waveguide or waveguides are exposed in a section between the front face of the fixing member and the coupling end face of the base member. During a subsequent polishing operation, there is the risk of the optical waveguides breaking off on the edge of the front face pointing in the direction of the optical waveguide.
From Published European Patent Application EP 0 760 488 A1 there is also known a fiber-optic endpiece which has a base member having a coupling end face and a depression. V-shaped grooves for holding optical fibers are provided in this depression. The optical fibers are pressed perpendicular to their longitudinal direction into the grooves by a pressure member having a press-on face and a front end face. The optical fibers are subsequently fixed permanently with an adhesive. The coupling end face of the base member, and the front end face of the pressure member lie in a common plane in this case. During production of this endpiece, it is necessary to maintain an external pressure force on the pressure member until the adhesive has hardened. This entails relatively long cycle and production times and furthermore makes it necessary to provide special production devices.
It is accordingly an object of the invention to provide a cost-effective fiber-optic endpiece which overcomes the above-mentioned disadvantages of the heretofore-known endpieces of this general type, and in which the optical waveguide is fixed uniformly along its contact lines in the form of a three-point mounting. The optical waveguide should be fixed up to its end, such that the end lies in the plane of a coupling end face, and such that the end is thereby protected against local overloading or overstressing by a tilting of the fixing member and/or against undesired stresses during the polishing operation.
With the foregoing and other objects in view there is provided, in accordance with the invention, a fiber-optic endpiece, which includes:
a base member having a coupling end face, the base member formed with a depression defining a bottom surface and lateral guide structures, the bottom surface formed with a groove for accepting the optical waveguide, the depression defining a longitudinal direction;
a fixing member having a front face, a rear face and guide faces, the fixing member being insertable into the depression along the lateral guide structures and defining an inserted position, the guide faces being adapted to the guide structures and interacting with the guide structures, the fixing member, when in the inserted position, being clamped in the depression for holding the optical waveguide in the groove;
the depression, the groove and the optical waveguide extending to the coupling end face;
the coupling end face and the front face defining a common plane, when the fixing member is in the inserted position; and
the depression and the fixing member having respective cross sections, at least one of the respective cross sections diminishing in the longitudinal direction and having a side with a reduced cross section opposite from the coupling end face.
In other words, the object of the invention is achieved by providing the reduced cross section of the depression and/or of the fixing member such that it is opposite i.e. facing away from the coupling end face, and by providing the coupling end face of the base member, and the front face of the clamped fixing member such that they lie in a common plane.
Providing the front face of the clamped fixing member and of the coupling end face of the base member in a common plane creates a common coupling and processing face. After joining the base member and the fixing member, the optical waveguide can be polished at this face without any disadvantageous effects.
Due to the fact that the reduced cross section of the depression and/or of the fixing member is averted from the coupling end face, the fixing member must be pushed into the depression from the side of the coupling end face. This permits the exchange of defective optical waveguides at a later point in time. After the fixing member has been pushed out of the depression, the defective optical waveguide can be removed and exchanged for a non-defective one. If the fixing member projects beyond the coupling end face after being pushed in anew, the common coupling and processing face is created by a subsequent polishing.
An advantageous embodiment of the invention has a plurality of V-shaped grooves, running in a plane and parallel to one another, for a corresponding number of optical waveguides. The advantageous embodiment also has aligning devices which run parallel to the V-shaped grooves and are provided on the coupling end face. The aligning devices are provided in the plane of the grooves. As a result, any adjustment work, that is possibly required during the production process, can refer to a single plane as a reference plane.
In accordance with a further feature of the invention, the respective cross sections are trapezoidal cross sections transverse to the longitudinal direction. The trapezoidal cross sections have a bottom side at the bottom surface and a top side. The bottom side is wider than the top side.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in fiber-optic endpiece, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.